POS1078 COMPARISON OF PATIENTS WITH AXIAL PsA AND PATIENTS WITH axSpA AND CONCOMITANT PSORIASIS
Authors: A. Regierer, A. Weiß, X. Baraliakos, F. Behrens, D. Poddubnyy, G. Schett, H. M. Lorenz, M. Worsch, A. Strangfeld
Journal: Annals of the Rheumatic Diseases (2022)

Background Psoriatic arthritis (PsA) is a chronic inflammatory disease affecting the peripheral and axial musculoskeletal system as well as skin and nails. Diagnostic criteria of axial PsA (axPsA) are not well defined. Treatment strategy is mostly based on evidence generated for axial spondyloarthritis (axSpA), as only rare clinical trial data for axPsA exist. However, it is still unclear whether axSpA with concomitant psoriasis (axSpA/pso) is the same as axPsA. Objectives To compare PsA patients with axial manifestations with axSpA patients with concomitant psoriasis. Methods RABBIT-SpA is a prospective longitudinal cohort study including PsA and axSpA patients enrolled at start of a new conventional treatment or b/tsDMARD treatment. Two definitions of axPsA were used: Clinical definition: documentation of axial manifestation as diagnosed by a rheumatologist Radiographic definition: presence of sacroiliitis according to modified NY criteria (mNYc). axSpA patients were stratified into axPsA/pso (with psoriasis either in patient history or present) and axSpA. Results Psoriasis was documented in 182/1407 axSpA patients (13%). Of 1355 PsA patients, 295 (22%) fulfilled the clinical definition of axPsA. Using the radiographic definition, 127 (9%) PsA patients fulfilled mNYc, 230 (17%) did not fulfil mNYc and 998 (74%) did not undergo radiographic evaluation. AxSpA/pso patients differed from axPsA regardless of the definition (Table 1). axPsA patients were older, less often HLA-B27 positive, and peripheral manifestations were much more often present in axPsA than in axSpA/pso. Uveitis and inflammatory bowel disease were more common in axSpA/pso. Table 1. Baseline characteristics of axSpA/pso patients and clinical resp. radiographic defined axPsA. axSpA/pso axPsA/clin axPsA/rad N 182 295 127 female gender, n (%) 80 (44) 178 (60.3) 80 (63) age, mean (SD) 47 (12.8) 51.1 (11.3) 51.6 (11.4) HLA-B27 positive, n (%) 106 (67.1) 44 (22.7) 28 (32.9) CRP mg/l, mean (SD) 8.7 (14.6) 7.1 (11.8) 6.9 (11.5) CRP ≥5 mg/l, n (%) 70 (42.4) 106 (40) 50 (45.9) uveitis ever, n (%) 26 (14.3) 10 (3.4) 7 (5.5) IBD ever, n (%) 13 (7.1) 14 (4.7) 7 (5.5) ≥3 comorbidities, n (%) 48 (26.4) 117 (39.7) 48 (37.8) peripheral manifestations, n (%) 65 (36.3) 251 (85.1) 109 (85.8) enthesitis, n (%) 29 (16.2) 77 (26.4) 32 (25.4) number of sites with enthesitis, mean (SD) 0.5 (1.6) 0.9 (2.2) 0.9 (1.9) affected joints, n (%) 53 (29.6) 234 (80.1) 102 (80.3) number of affected joints, mean (SD) 1.4 (3.7) 6.8 (8.4) 5 (5.9) physician global disease activity, mean (SD) 5.6 (2.1) 5.6 (1.9) 5.6 (2) patient global disease activity, mean (SD) 5.4 (2.6) 5.9 (2.3) 5.8 (2.2) patient pain, mean (SD) 5.5 (2.6) 5.7 (2.3) 5.7 (2.2) sakroiliitis, n (%) 124 (84.4) 97 (56.1) 127 (100) clinical axial definition, n (%) n.d. 295 (100) 97 (76.4) In contrast, disease activity measured by physician global as well as patient global, and patient pain were similar in axSpA/pso and axPsA. Conclusion Regardless whether clinical or radiographic definitions of axPsA were used, differences to axSpA/pso patients were identified. These data indicate a need for a specific diagnostic, and a potentially more targeted treatment approach for axPsA. Disclosure of Interests Anne Regierer Grant/research support from: RABBIT-SpA is supported by a joint, unconditional grant from AbbVie, Amgen, Biogen, Hexal, Janssen-Cilag, Lilly, MSD, Novartis, Pfizer, UCB and Viatris., Anja Weiß Grant/research support from: RABBIT-SpA is supported by a joint, unconditional grant from AbbVie, Amgen, Biogen, Hexal, Janssen-Cilag, Lilly, MSD, Novartis, Pfizer, UCB and Viatris., Xenofon Baraliakos: None declared, Frank Behrens: None declared, Denis Poddubnyy: None declared, Georg Schett: None declared, Hanns-Martin Lorenz: None declared, Matthias Worsch: None declared, Anja Strangfeld Grant/research support from: RABBIT-SpA is supported by a joint, unconditional grant from AbbVie, Amgen, Biogen, Hexal, Janssen-Cilag, Lilly, MSD, Novartis, Pfizer, UCB and Viatris.